Risk of COVID-19 among unvaccinated and vaccinated patients with systemic lupus erythematosus: a general population study

OBJECTIVE: To compare the risk of SARS-CoV-2 infection and its related severe sequelae between patients with systemic lupus erythematosus (SLE) and the general population according to COVID-19 vaccination status. METHODS: We performed cohort studies using data from The Health Improvement Network to compare the risks of SARS-CoV-2 infection and severe sequelae between patients with SLE and the general population. Individuals aged 18–90 years with no previously documented SARS-CoV-2 infection were included. We estimated the incidence rates and HRs of SARS-CoV-2 infection and severe sequelae between patients with SLE and the general population according to COVID-19 vaccination status using exposure score overlap weighted Cox proportional hazards model. RESULTS: We identified 3245 patients with SLE and 1 755 034 non-SLE individuals from the unvaccinated cohort. The rates of SARS-CoV-2 infection, COVID-19 hospitalisation, COVID-19 death and combined severe outcomes per 1000 person-months were 10.95, 3.21, 1.16 and 3.86 among patients with SLE, and 8.50, 1.77, 0.53 and 2.18 among general population, respectively. The corresponding adjusted HRs were 1.28 (95% CI: 1.03 to 1.59), 1.82 (95% CI: 1.21 to 2.74), 2.16 (95% CI: 1.00 to 4.79) and 1.78 (95% CI: 1.21 to 2.61). However, no statistically significant differences were observed between vaccinated patients with SLE and vaccinated general population over 9 months of follow-up. CONCLUSION: While unvaccinated patients with SLE were at higher risk of SARS-CoV-2 infection and its severe sequelae than the general population, no such difference was observed among vaccinated population. The findings indicate that COVID-19 vaccination provides an adequate protection to most patients with SLE from COVID-19 breakthrough infection and its severe sequelae.